Said Bengamra

International audienceLe bassin versant du Nekor, localisé dans le Nord-Est du Maroc et dans la partie orientale des montagnes du Rif, s‘ouvre sur la mer Méditerranée par une large plaine alluviale. Cette zone d‘étude présente une géomorphologie complexe à terrains très accidentés, une diversité des formations lithologiques avec une prédominance des formations schisteuses à assises friables. En effet, ce bassin versant fait l‘objet d‘une forte dégradation moyenne annuelle, l‘une des plus élevées au monde. Le bassin du Nekor est caractérisé par des phénomènes d‘érosion importants sous forme de masse ou de ravins.Le climat de la région est de type méditerranéen semi-aride à aride avec le passage de grandes perturbations associées à des précipitations souvent intenses en hiver. Nous sous sommes basés sur cette situation complexe pour caractériser des eaux des puits et des sources d‘eaux situés au niveau de ce bassin, et qui sont utilisés par la population locale pour s‘approvisionner e...

The eastern region of Morocco is characterized by an arid to semi-arid climate. It is often confronted with heavy rainfall episodes that can generate floods that can cause adverse human and property damage. This work studies hydrological risk in the SidiBoulenouar area (Oujda province) to model floods and map risk areas. The method used is to determine the watersheds and their watercourses, then to calculate the flows with the mathematical formulas. Topographic data were extracted from a 12.5-m resolution DEM derived from the ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer). GDEM (Global DEM). The DEM was used to delimit the hydrographic network with ArcMap software. The use of HEC RAS 1D was necessary to delimit the flooding area. The results of the 1D hydraulic modeling of the centennial flood showed that four ephemeral watercourses landlock the rural area of SidiBoulenouar at the time of the floods.

In the Mediterranean region, the magnitude of floods and their frequencies imposes their consideration by forest managers and local decision makers. In this context, the identification of areas expected to be affected by floods is a fundamental information to improve the management of this risk. The methodology developed in this paper allows presenting a tool to assess flooding risk across the river basin. It is based on the idea that the risk of flooding is the resultant of the random factor (frequency of natural phenomena) and the vulnerability factor (sensitivity of land use). The purpose of this article is to make a flood risk map of the Oued Laou plain, which includes the two urban areas Oued Laou. The realization of this map requires a hydrological study to calculate the maximum capacity of the region and a hydraulic study to determine the speed and height of the centennial flood of Oued Laou using the Iber 2.0.3 software. The results will be presented as thematic maps, using ...

The implementation of suitable monitoring and protection actions is fundamental for protect freshwater resources in costal aquifers. Electrical resistivity tomography (ERT), has proved, in many case, to be very effective for illustrating with higher resolution near-surface resistivity anomalies for a wide range of environmental problems, including saltwater intrusion. According ERT models obtained in this survey, the saltwater intrusion in Ghis-Nekor aquifer can be explained both by the presence of deep faults that cross the impermeable layers of silts and clays, or by a lateral facies change in the shallow deposits favoring saltwater intrusion into the aquifer

The study area which is part of the Saidia littoral consists of two parts: a fluvial portion between the bypass bridge and the mouth of the Moulouya river over a length of 5 km and littoral part between the Saidia Marina port and the port of marine fisheries of Cap de l’Eau. Sea (L1 to L25) withdrawals have been made according to the radial oriented perpendicularly to the shore line. The average distance between two radial is of approximately 1,2 Km and between two successive samples is about 800 m. sampling in the river ( F1 to F5) were made in the minor bed of Oued Moulouya with 550 metres spacing. Following this oceanographic campaign, the sedimentological characterization of samples is based on granulometric, mineralogical, morphoscopic and calcimetric tests. The granulometric study showed that these sediments consist essentially of moderately graded sands. As to the morphoscopy of quartz, revealed the prevailence of the NU type to the west of the estuary of Moulouya river resul...